title: Umbelliferone induces changes in the structure and pharmacological activities of Bn IV, a phospholipase A(2) isoform isolated from Bothrops neuwiedi.
abstract: In this paper was demonstrated that umbelliferone induces changes in structure and pharmacological activities of Bn IV, a lysine 49 secretory phospholipase A(2) (sPLA2) from Bothrops neuwiedi. Incubation of Bn IV with umbelliferone virtually abolished platelet aggregation, edema, and myotoxicity induced by native Bn IV. The amino acid sequence of Bn IV showed high sequence similarities with other Lys49 sPLA2s from B. jararacussu (BthTx-I), B. pirajai (PrTx-I), and B. neuwiedi pauloensis (Bn SP6 and Bn SP7). This sPLA2 also has a highly conserved C-terminal amino acid sequence, which has been shown as important for the pharmacological activities of Lys49 sPLA2. Sequencing of Bn IV previously treated with umbelliferone revealed modification of S(1) and S(20). Fluorescent spectral analysis and circular dichroism (CD) studies showed that umbelliferone modified the secondary structure of this protein. Moreover, the pharmacological activity of Bn IV is driven by synergism of the C-terminal region with the α-helix motifs, which are involved in substrate binding of the Asp49 and Lys49 residues of sPLA2 and have a direct effect on the Ca(2+)-independent membrane damage of some secretory snake venom PLA2. For Bn IV, these interactions are potentially important for triggering the pharmacological activity of this sPLA2.
authors.affiliation: Centro de Ciências Biológicas e da Saúde, Universidade Presbiteriana Mackenzie, São Paulo, Brazil. mhtjpn@yahoo.com
authors.forename: Daniela de Oliveira
authors.initials: Dde O
authors.lastname: Toyama
authors.forename: Eduardo Britto dos Santos
authors.initials: EB
authors.lastname: Diz Filho
authors.forename: Benildo Sousa
authors.initials: BS
authors.lastname: Cavada
authors.forename: Bruno Anderson Matias
authors.initials: BA
authors.lastname: da Rocha
authors.forename: Simone Cristina Buzzo
authors.initials: SC
authors.lastname: de Oliveira
authors.forename: Camila Aparecida
authors.initials: CA
authors.lastname: Cotrim
authors.forename: Veronica Cristina Gomes
authors.initials: VC
authors.lastname: Soares
authors.forename: Plínio
authors.initials: P
authors.lastname: Delatorre
authors.forename: Sérgio
authors.initials: S
authors.lastname: Marangoni
authors.forename: Marcos Hikari
authors.initials: MH
authors.lastname: Toyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017837:Bothrops; D002942:Circular Dichroism; D004487:Edema / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D054467:Phospholipases A2 / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism* / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA; D013050:Spectrometry, Fluorescence; D014468:Umbelliferones / Q000378:metabolism*
chemical_list: D014468:Umbelliferones; C031477:7-hydroxycoumarin; D054467:Phospholipases A2